<template>
   <!-- 头部部分 -->
    <header class="header">
      <h1>todos</h1>
      <input class="new-todo" 
      placeholder="请输入任务名称" 
      autofocus 
      @keyup.enter='addList'
      v-model.trim="todoName"
      />
    </header>
</template>
 
<script>
export default {
  name: "TodoListHeader",
  data() {
    return {
      todoName :'',
    };
  },
 
  methods: {
    addList(){
      if(!this.todoName) return alert('内容不能为空')
      this.$emit('addList',this.todoName)
      this.todoName=''
    }
  }
};
</script>

<style scoped>
     
</style>